# UpdateFn

# Type Alias: UpdateFn\<TValue\>

```ts
type UpdateFn<TValue> = (previousValue) => TValue;
```

Defined in: [types.public.ts:3](https://github.com/TanStack/form/blob/main/packages/form-core/src/types.public.ts#L3)

## Type Parameters

### TValue

`TValue`

## Parameters

### previousValue

`TValue`

## Returns

`TValue`